1. Field of the Invention
The present invention relates to an inductance coil such as a common mode choke coil.
2. Description of Related Art
Common mode choke coils have to satisfy the safety standard, and in order to do that, the core and the coil have to be kept at a distance to assure insulation between the core and the coil. For this reason, there had been conventionally a limit in the number of times of winding the coil. To fill the gap between the core and the coil with insulating resin, however, has replaced the way of winding the coil within the limit, and as a result, it has become possible to obtain a compact choke coil wherein a coil is wound a larger number of times and the inductance is large. However, there is still a problem on choke coils for which divided type cores are used. Specifically, with regard to a type of choke coil where a couple of U-shaped cores (for example, cores 10 as shown in FIG. 1) are inserted in a center hole of the bobbin with the end faces adherent to each other to form a closed-loop magnetic path, when the cast: insulating resin hardens, the cores slip out of place because of the stress caused by shrinkage of the resin, impairing the adhesion of the end faces. Consequently, the inductance is lowered. Although the insulating resin is cast for the purpose of raising the inductance, it is difficult to accomplish the purpose in this situation.